Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
COVID‐19 indicates coronavirus disease 2019. Data derived from https://www.cdc.gov/coronavirus/2019‐ncov/lab/resources/antibody‐tests‐guidelines.html/.
